TY - JOUR

T1 - Gravitational waves and mass ejecta from binary neutron star mergers

T2 - Effect of the spin orientation

AU - Chaurasia, Swami Vivekanandji

AU - Dietrich, Tim

AU - Ujevic, Maximiliano

AU - Hendriks, Kai

AU - Dudi, Reetika

AU - Fabbri, Francesco Maria

AU - Tichy, Wolfgang

AU - Bruegmann, Bernd

PY - 2020/7/30

Y1 - 2020/7/30

N2 - We continue our study of the binary neutron star parameter space by investigating the effect of the spin orientation on the dynamics, gravitational wave emission, and mass ejection during the binary neutron star coalescence. We simulate seven different configurations using multiple resolutions to allow a reasonable error assessment. Due to the particular choice of the setups, five configurations show precession effects, from which two show a precession ("wobbling") of the orbital plane, while three show a "bobbing" motion; i.e., the orbital angular momentum does not precess, while the orbital plane moves along the orbital angular momentum axis. Considering the ejection of mass, we find that precessing systems can have an anisotropic mass ejection, which could lead to a final remnant kick of similar to 40 km/s for the studied systems. Furthermore, for the chosen configurations, antialigned spins lead to larger mass ejecta than aligned spins, so that brighter electromagnetic counterparts could be expected for these configurations. Finally, we compare our simulations with the precessing, tidal waveform approximant IMRPhenomPv2_NRTidalv2 and find good agreement between the approximant and our numerical relativity waveforms with phase differences below 1.2 rad accumulated over the last similar to 16 gravitational wave cycles.

AB - We continue our study of the binary neutron star parameter space by investigating the effect of the spin orientation on the dynamics, gravitational wave emission, and mass ejection during the binary neutron star coalescence. We simulate seven different configurations using multiple resolutions to allow a reasonable error assessment. Due to the particular choice of the setups, five configurations show precession effects, from which two show a precession ("wobbling") of the orbital plane, while three show a "bobbing" motion; i.e., the orbital angular momentum does not precess, while the orbital plane moves along the orbital angular momentum axis. Considering the ejection of mass, we find that precessing systems can have an anisotropic mass ejection, which could lead to a final remnant kick of similar to 40 km/s for the studied systems. Furthermore, for the chosen configurations, antialigned spins lead to larger mass ejecta than aligned spins, so that brighter electromagnetic counterparts could be expected for these configurations. Finally, we compare our simulations with the precessing, tidal waveform approximant IMRPhenomPv2_NRTidalv2 and find good agreement between the approximant and our numerical relativity waveforms with phase differences below 1.2 rad accumulated over the last similar to 16 gravitational wave cycles.

U2 - 10.1103/PhysRevD.102.024087

DO - 10.1103/PhysRevD.102.024087

M3 - Article

VL - 102

JO - Physical Review D

JF - Physical Review D

SN - 1550-7998

IS - 2

M1 - 024087

ER -